Our old casement window panes are fixed in by small metal tabs, I do not know how to describe them better - there are no small nails holding the glass in, just these very small (size of a small finger nail) pieced of metal. The beads are very narrow and the glass is possibly only 2mm thick. I am hoping I could fix the glass in in the same way, but need to know what it is I am looking for/purchase, Any ideas?